This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 2 |
| 7 | 8 |
| 8 | 48 |
| 9 | 450 |
| 10 | 5752 |
| 11 | 90555 |
| 12 | 1612917 |
| 13 | 31297424 |
| 14 | 652159986 |
| 15 | 14499787794 |
| 16 | 342646826428 |